(a) Field of the Invention:
The invention relates to novel 1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones having an aryl or heteroaryl group in the 6-position, and to the preparation thereof and the use thereof as phosphodiesterase inhibitors.
(b) Information Disclosure Statement:
Lesher et al. U.S. Pat. No. 4,294,837, issued Oct. 13, 1981, discloses compounds of the formula: ##STR2## where Z is O or S, Q is hydrogen or lower-alkyl, R.sub.1 and R.sub.3 each are hydrogen, lower-alkyl, lower-hydroxyalkyl, 2,3-dihydroxypropyl, lower-alkoxyalkyl or Y-NB where Y is lower-alkylene having at least two carbon atoms between its connecting linkages and NB is di-(lower-alkyl)amino or 4-morpholinyl, at least one of R.sub.1 or R.sub.3 being hydrogen, and PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, or pharmaceutically-acceptable acid-addition salts thereof. The compounds of the above formula are useful as cardiotonic agents. At column 20, lines 26-27 is disclosed the compound 1,3-dihydro-5-methyl-6-(4-pyridinyl)-2H-imidazo[4,5-b]-pyridin-2-one, identified by name only.